BerntR said:
Thanks for the tip, I'll look into that when fine tuning starts.
terry j said:
The CAD design is the bible when it comes to building anything but particularly something a little more involved such as this. I followed my initial plans religiously and always double checked every cut of every piece of MDF and if it wasn't spot on or very close I redid. If I hadn't followed this simple rule then the errors tend to compound and build, after that things just don't fit correctly.
Careful planning is your very best friend with any build.
terry j said:
Ouch now there's a question.
Assuming an average of about 2 hours per evening, which sounds about right considering some days I spent over 12 hours working on them and on others nothing, then spread that over a period of 7 months. So I'd estimate about 300-400 hours on construction and finishing with plenty more to do on the unfinished speaker. Its scary when its put like that because you just chip away at the project not really caring about time until you add it all up.
I also spent about 4 months of casual planning and designing before even buying the MDF. I guess there's about another 75-100 hours in that too.
Then factor in the time thats has been and is going to be spent working the crossovers, measuring and tweaking. Its starting to look like 1000 hours from start to finish would be a good ball park figure. That doesn't include the miscellaneous but related projects such as the amps and pre-amp.
You're really starting to depress me now, or rather I'm depressing myself!
pinkmouse said:Brilliant! The quality of your construction continues to amaze me.
But fix the leak - "Don't spoil the ship for a ha'porth 'o tar"
Thanks Al.
Late last night I finished up fixing the leaks with another application of hot melt glue after removing the existing stuff that had failed due to me pulling the wires back through when fixing the drivers. Testing the integrity of each enclosure shows its as it should be now.
I've also just rigged it up and am using the last known half decent crossover that I worked on during testing with just an TMW section of the speaker. It obviously needs work before its up to scratch with the WMTMW(this is the first time I've heard the whole speaker) but adjusting to match the simulation work I did in LEAP has really brought out some strong qualities, I've also added some driver correction but I have to strongly question the accuracy of the measurements as I was in a big rush to listen to them and knowingly disregarded a couple of important but time consuming rules. After the initial excitement has dissipated I'll be much more systematic and ensure a good accurate foundation to work from.
With that said I can offer a few thoughts but this will hopefully improve as the true performance of the speaker is fully revealed with more careful and prolonged tweaking.
The bass is quite something, it has a fair amount grunt meaning extension and goes very loud, more than I was expecting, without compression but thats far from what is most impressive here. The overall tone and sense of pace is almost perfectly judged, another thing is it doesn't really sound like bass being reproduced by a loudspeaker if that makes sense, the best way to describe it is free and even without any emphasis on a particular tone or tones. The pair of 8" AT's also respond well to a bit of low end EQ and can be made to quite easily reach down to 25hz and still go loud. This was just a little experiment to see what they could handle and personally I prefer it without the EQ, especially considering that each of the 8's is running up to 200hz+. But for home theater and until I build a sub then I could do a preset with the bass boost and be quite satisfied.
Even in this early stage I can see the bass being a standout quality.
The mids are growing on me and I really hope with continued tweaking that they will improve. I've tried alsorts to make them sound like the ATC 3" dome midrange(my fav mid) but they just don't and I think that's the problem, I'm expecting something thats from a rose tinted memory and an auditory memory at that which is notoriously useless. I remember saying that they lack dynamics and in comparison to the ATC's, which is a real fire cracker, they do. But things have improved, not massively, with the combining of two mids now working together instead of my initial assessment using one. Aside from the slight increase in dynamics with two drivers I certainly heared the mids become more present and larger in size.
But what they trade in dynamics and bite they certainly gain more insight and resolution. The 5" AT isn't a driver thats immediately impressive unlike the ATC but instead is quite unassuming and surprises with subtle details, a really well ordered and smooth sound as well as no end of naturalness.
I also note that you really have to sit back from the speaker (at least 2.5 meters) otherwise you can start to hear the MTM drawing attention to itself by colapsing the sound and drawing the midrange firmly to two definite points - the drivers. At distances of around 2.5meters and beyond it fills out into the room, completely away from the two drive units to create one source. Actually the sound as whole feels disjointed if you sit too close, this is definitely a far field speaker as it doesn't sound right otherwise.
For the tweeter the initial crossover point was 1.5Khz with some steep to very steep FIR filters but the RAAL seems to work very nicely even down to as low as 1.2Khz and still goes impressively loud(well beyond my comfort zone) with not a hint of harshness attributed to distortion and nor does the sound begin to compress, harden or otherwise at these high levels.
I did try it at 1Khz but when testing at the level as what I'd consider the maximum I'd expect from the speaker I noted a small amount harshness and the start of the whole sound coming from the tweeter colapsing back in itself and turning to noise. When going beyond that volume level it doesn't get louder it just gets noiser. As a side effect I noted just how tough these RAALs are, they can take some abuse and still sound great.
About the tweeter, this thing is amazing. Easily the most impressive element of the loudspeaker. It has a real quality way with the frequencies it deals with. I won't dribble on over this driver here as I did more than enough of that earlier on in this thread.
Considering the sound of the loudspeaker as a whole its apparent that this is a very low distortion design with a lot of headroom and a high resolution, smooth, always in control sound from top to bottom. Fortunately(or should that be unfortunately?) this is only a small taster of things to come where I haven't even began to touch upon what the system can really do once its brother joins for some stereo fun and a more solid foundation is laid and then subsequently tweaked.
m0tion said:
Hi Motion,
For testing I'm using 5 channels of GB300D amps, these are 300w/8ohm designs from Greg Ball and configured as monoblocks. These designs will also be the final amps used with the speakers. Its a little bit jury rigged at the minute because they're not fixed in their final enclosures yet but I'm working on that and will post something when they're looking a little more like amps rather than PCB's attached to heatsinks and a load of messy wires running around. Hopefully I'll have one of the 4 channel amps finished over the weekend.
Preamp is in the hands of Russ White who is still working away on a most impressive design. This going to kick major *** for anyone with active multiway designs and particularly those with digital crossovers. Much more on this at the right time.
And this IS as you say, only in mono. You're probably in for a pleasant surprise when you hook up the other channel. One loudspeaker always sounds underwhelming to me, no matter how good it is, then you connect up the other channel and have an 'oh wow' moment. I am often surprised at just how much better it sounds with 2 speakers instead of one.
They deserve to sound excellent though considering the time, effort and not to mention money you have spent on these.
They deserve to sound excellent though considering the time, effort and not to mention money you have spent on these.
Still playing...
Thinking about the mids and the lack of dynamics, I thought that maybe I'd over done it with all the foam that soaks up the rear wave. So I set about removing it(yet again!). To get an accurate idea of what was going on I needed to compare with and without so I left one with the foam and one without and just switched between the two using signal routing on the PC. That way you have an instant A/B.
Removing the foam has made a definite positive difference, sadly its a mix of both good and bad. First the bad; there's now a slightly shouty and forward character to the sound that seems to mask some fine detail but the upshot is dynamics and sense of attack and energy in the sound has been improved to the point where the driver with treatments sounds overly polite and maybe even slightly boring. Its not as smooth or even as it was before but its heading towards the sort of sound I prefer and is a step in the right direction. For now I'm going to do away with the all the foam except for that on the walls of the enclosure and then systematically add small amounts of foam, experimenting with different positions and maybe with different daming materials. Fingers crossed that something can which will keep the increased dynamics whilst cutting back on that shouty character I mentioned.
I also remember Vik saying I should've chamfered the rear of the mid driver opening so as to allow more room to breath. I now have to agree and think this would go someway to helping the overall sound. Its going to be tough to get the router into the right spot to accurately take material off but its doable with care so I'll give that a go over the weekend and report back.
Absolutely shattered, spent around 15 hours today listening and tweaking so I think its time for a little shut eye.
Thinking about the mids and the lack of dynamics, I thought that maybe I'd over done it with all the foam that soaks up the rear wave. So I set about removing it(yet again!). To get an accurate idea of what was going on I needed to compare with and without so I left one with the foam and one without and just switched between the two using signal routing on the PC. That way you have an instant A/B.
Removing the foam has made a definite positive difference, sadly its a mix of both good and bad. First the bad; there's now a slightly shouty and forward character to the sound that seems to mask some fine detail but the upshot is dynamics and sense of attack and energy in the sound has been improved to the point where the driver with treatments sounds overly polite and maybe even slightly boring. Its not as smooth or even as it was before but its heading towards the sort of sound I prefer and is a step in the right direction. For now I'm going to do away with the all the foam except for that on the walls of the enclosure and then systematically add small amounts of foam, experimenting with different positions and maybe with different daming materials. Fingers crossed that something can which will keep the increased dynamics whilst cutting back on that shouty character I mentioned.
I also remember Vik saying I should've chamfered the rear of the mid driver opening so as to allow more room to breath. I now have to agree and think this would go someway to helping the overall sound. Its going to be tough to get the router into the right spot to accurately take material off but its doable with care so I'll give that a go over the weekend and report back.
Absolutely shattered, spent around 15 hours today listening and tweaking so I think its time for a little shut eye.
Shin,
It's possible those midranges need a lot more breakin before they open up. If possible can you run them full range for a couple of days with various music sources from the output of an old receiver tuned to various music stations. That should give them a good workout. You can run them at modest levels when you are at work and then come home and turn them up a little to compare the sound for various break in periods.
I'm thinking that the midrange frequency range with crossovers may not break them in as well or as fast as a full range signal.
Hezz
It's possible those midranges need a lot more breakin before they open up. If possible can you run them full range for a couple of days with various music sources from the output of an old receiver tuned to various music stations. That should give them a good workout. You can run them at modest levels when you are at work and then come home and turn them up a little to compare the sound for various break in periods.
I'm thinking that the midrange frequency range with crossovers may not break them in as well or as fast as a full range signal.
Hezz
Bratislav said:
Time to try open baffles methinks
Oh.. that is just *E V I L*
Alternatively:
http://www.hytechsales.com/prodsc.html
Visually, it certainly seems to be coming along nicely!
(..yeah, the foam waveguides are a little odd.. but no doubt worth it for the sound.)
ScottG said:
I've looked at that stuff on more than one occasion but the shipping is a killer and there's no UK or even European distro's.
Visually, it certainly seems to be coming along nicely!
Thanks Scott, the waveguides are a bit odd looking but I think they're essential to hear the RAAL at its best - that and the fact that the RAAL runs about 9dB hot on the upper end without it!
Open Baffle? I'm guessing...
Shin's baffles are easily detached from the boxes and it wouldn't be that hard to try....just a couple of days work to build a frame that would align things as they are now and hold up something that tall and heavy.
This is of course the first thing I would want to after getting them fired up for the first time after a design build process that lasted nearly a year.
C
Shin's baffles are easily detached from the boxes and it wouldn't be that hard to try....just a couple of days work to build a frame that would align things as they are now and hold up something that tall and heavy.
This is of course the first thing I would want to after getting them fired up for the first time after a design build process that lasted nearly a year.
C
Hi Shin,
your stuffing experiences remind me of a fad around 15 years ago, when Jimmy Hughes advocated removing all stuffing for a more dynamic, lively sound. Obviously, the trade off was the same then as now.
IMO the correct approach is to try different levels of stuffing; pain as it is with 4 mid enclosures.
Looking great mate.
your stuffing experiences remind me of a fad around 15 years ago, when Jimmy Hughes advocated removing all stuffing for a more dynamic, lively sound. Obviously, the trade off was the same then as now.
IMO the correct approach is to try different levels of stuffing; pain as it is with 4 mid enclosures.
Looking great mate.
ShinOBIWAN said:
The additive should be a LOT less (it weighs almost nothing).. (and looking at their sound coat version it seems to be a 5/1 mixture - i.e. 5 times the normal quantity for a gallon of paint).
http://www.hytechsales.com/buy_ceramicadditive.html
Also search for Tempcoat and other brands of similar paint. They might not be quite as effective.. BUT its usually a question of quantity (i.e. more should produce a similar result).
EDIT: This might be a viable source:
http://www.thermilate.com/
These people use it in their pricier loudspeakers:
http://www.totemacoustic.com/english/index_eng.htm
Multiple coats (3-5) on all interior surfaces should give you what you are looking for.
Hallo Shin,
i haven't read the complete thread but i really have to say that i very much appreciate your work - wonderful design and building!
And also the finsish is more than impressive.
But here some feedback from my experience on your midrange issue:
Knowing both, the C-Quenze, the ATC midrange and also others my conclusions today are:
- the C-Quenze driver is the perfect driver in an extremely broadbanded application. It doesn't like to be cut off, neither at the upper nor at the lower end. The more it is cut off the worse it will sound. It is best used with the fastest tweeters crossed over to it above 3.5 kHz. It will even handle a x-over point around 5 kHz easily! It doesn't really like filters steeper than 6 or a very soft 9 dB (needed for Kapton voice coil former).
Being used that way there's nothing compareable out there!
We have measured it's dynamics and we have found that it is even faster than most tweeters are! There are very few (tweeters!) that can compete with it's speed. It's resolution abilities are, used properly, far beyond any other midrange i know, which does not pay for it's resolution abilities, due to the hard membran material, with heavy brakeup modes.
- the ATC is the perfect and in my eyes the best real midrange. It has a perfect "midrange behaviour" and the question is how to protect it from the lowest frequencies and to avoid getting into that extremly long decay point at around 5 kHz without disturbing to much it's nearly perfect natural midrange abilities. It is less demanding than the C-Quenze regarding definition of x-over point to tweeter. Can be crossed over lower to tweeter than C-Quenze.
So the summary for me is:
C-Quenze for:
Ultimative 2-way and 2-1/2 way systems with high x-over points
ATC SM75 for:
Ultimative 3- and 4-way systems
But as you already have decided to use the C-Quenze in your system as midrange i think, that even if the initial idea was to have the RAAL working down to 1.5 kHz to get closer to a "point source" it would be worth trying to put the x-over point significantly higher and taking the risk to cause other problems which i expect to be less disturbing than having a midrange that seems to lack dynamics (which it surely doesn't!).
I can tell all that because we have made pretty much the same experience with the C-Quenze midrange as you decribe when we worked with it in the beginning but we have solved the issues in the meantime going to higher x-over points ... and using nearly no damping material in its box.
Concerning x-over design:
I could imaging that at least to find the best concept for the x-over design of your TMT, an active programmable x-over would help a lot. And they are less expensive than one would expect ...
Finally, another point which should not be underestimated is that the Audiotechnology drivers really take their time to brake in...
I wish you all the best and good luck for your ambitous project!
Even if i am very rarely looking in the diyaudio, please leave me a message if you are interested in a more detailed feedback concerning the experience with the the C-Quenze mid.
i haven't read the complete thread but i really have to say that i very much appreciate your work - wonderful design and building!
And also the finsish is more than impressive.
But here some feedback from my experience on your midrange issue:
Knowing both, the C-Quenze, the ATC midrange and also others my conclusions today are:
- the C-Quenze driver is the perfect driver in an extremely broadbanded application. It doesn't like to be cut off, neither at the upper nor at the lower end. The more it is cut off the worse it will sound. It is best used with the fastest tweeters crossed over to it above 3.5 kHz. It will even handle a x-over point around 5 kHz easily! It doesn't really like filters steeper than 6 or a very soft 9 dB (needed for Kapton voice coil former).
Being used that way there's nothing compareable out there!
We have measured it's dynamics and we have found that it is even faster than most tweeters are! There are very few (tweeters!) that can compete with it's speed. It's resolution abilities are, used properly, far beyond any other midrange i know, which does not pay for it's resolution abilities, due to the hard membran material, with heavy brakeup modes.
- the ATC is the perfect and in my eyes the best real midrange. It has a perfect "midrange behaviour" and the question is how to protect it from the lowest frequencies and to avoid getting into that extremly long decay point at around 5 kHz without disturbing to much it's nearly perfect natural midrange abilities. It is less demanding than the C-Quenze regarding definition of x-over point to tweeter. Can be crossed over lower to tweeter than C-Quenze.
So the summary for me is:
C-Quenze for:
Ultimative 2-way and 2-1/2 way systems with high x-over points
ATC SM75 for:
Ultimative 3- and 4-way systems
But as you already have decided to use the C-Quenze in your system as midrange i think, that even if the initial idea was to have the RAAL working down to 1.5 kHz to get closer to a "point source" it would be worth trying to put the x-over point significantly higher and taking the risk to cause other problems which i expect to be less disturbing than having a midrange that seems to lack dynamics (which it surely doesn't!).
I can tell all that because we have made pretty much the same experience with the C-Quenze midrange as you decribe when we worked with it in the beginning but we have solved the issues in the meantime going to higher x-over points ... and using nearly no damping material in its box.
Concerning x-over design:
I could imaging that at least to find the best concept for the x-over design of your TMT, an active programmable x-over would help a lot. And they are less expensive than one would expect ...
Finally, another point which should not be underestimated is that the Audiotechnology drivers really take their time to brake in...
I wish you all the best and good luck for your ambitous project!
Even if i am very rarely looking in the diyaudio, please leave me a message if you are interested in a more detailed feedback concerning the experience with the the C-Quenze mid.
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